Origin of stomach bug outbreak remains a mystery

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Published
4:02 pm EDT, Wednesday, July 31, 2013

In this image provided by the Centers for Disease Control and Prevention, a photomicrograph of a fresh stool sample, which had been prepared using a 10% formalin solution, and stained with modified acid-fast stain, reveals the presence of four Cyclospora cayetanensis oocysts in the field of view. Iowa and Nebraska health officials said Tuesday, July 30, 2013, that a prepackaged salad mix is the source of a cyclospora outbreak that sickened more than 178 people in both states. Cyclospora is a rare parasite that causes a lengthy gastrointestinal illness. (AP Photo/Centerd for Disease Control and Prevention)

In this image provided by the Centers for Disease Control and Prevention, a photomicrograph of a fresh stool sample, which had been prepared using a 10% formalin solution, and stained with modified acid-fast

In this image provided by the Centers for Disease Control and Prevention, a photomicrograph of a fresh stool sample, which had been prepared using a 10% formalin solution, and stained with modified acid-fast stain, reveals the presence of four Cyclospora cayetanensis oocysts in the field of view. Iowa and Nebraska health officials said Tuesday, July 30, 2013, that a prepackaged salad mix is the source of a cyclospora outbreak that sickened more than 178 people in both states. Cyclospora is a rare parasite that causes a lengthy gastrointestinal illness. (AP Photo/Centerd for Disease Control and Prevention)

In this image provided by the Centers for Disease Control and Prevention, a photomicrograph of a fresh stool sample, which had been prepared using a 10% formalin solution, and stained with modified acid-fast

In this image provided by the Centers for Disease Control and Prevention, a photomicrograph of a fresh stool sample, which had been prepared using a 10% formalin solution, and stained with modified acid-fast stain, reveals the presence of four Cyclospora cayetanensis oocysts in the field of view. Iowa and Nebraska health officials said Tuesday, July 30, 2013, that a prepackaged salad mix is the source of a cyclospora outbreak that sickened more than 178 people in both states. Cyclospora is a rare parasite that causes a lengthy gastrointestinal illness. (AP Photo/Centerd for Disease Control and Prevention)

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